<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>性能监控</title>
    <style type="text/css">
      html,
      body {
        margin: 0;
        height: 100%;
      }

      canvas {
        display: block;
      }
    </style>
  </head>
  <body onload="draw();"></body>
  <script src="https://cdn.bootcdn.net/ajax/libs/three.js/r128/three.js"></script>
  <script src="./js/controls/TrackballControls.js"></script>
  <script src="./js/libs/stats.min.js"></script>
  <script>
    var renderer;
    function initRender() {
      renderer = new THREE.WebGLRenderer({ antialias: true });
      renderer.setSize(window.innerWidth, window.innerHeight);
      document.body.appendChild(renderer.domElement);
    }

    var camera;
    function initCamera() {
      camera = new THREE.PerspectiveCamera(
        45,
        window.innerWidth / window.innerHeight,
        1,
        10000
      );
      camera.position.set(0, 0, 400);
    }

    var scene;
    function initScene() {
      scene = new THREE.Scene();
    }

    var light;
    function initLight() {
      scene.add(new THREE.AmbientLight(0x404040));

      light = new THREE.DirectionalLight(0xffffff);
      light.position.set(1, 1, 1);
      scene.add(light);
    }

    function initModel() {
      var map = new THREE.TextureLoader().load("./img/1.jpg");
      var material = new THREE.MeshLambertMaterial({ map: map });

      var cube = new THREE.Mesh(
        new THREE.BoxGeometry(100, 200, 100, 1, 1, 1),
        material
      );
      scene.add(cube);
    }

    //初始化性能插件
    var stats;
    function initStats() {
      stats = new Stats();
      document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;
    function initControls() {
      controls = new THREE.TrackballControls(camera, renderer.domElement);
      //旋转速度
      controls.rotateSpeed = 5;
      //变焦速度
      controls.zoomSpeed = 3;
      //平移速度
      controls.panSpeed = 0.8;
      //是否不变焦
      controls.noZoom = false;
      //是否不平移
      controls.noPan = false;
      //是否开启移动惯性
      controls.staticMoving = false;
      //动态阻尼系数 就是灵敏度
      controls.dynamicDampingFactor = 0.3;
      //未知，占时先保留
      //controls.keys = [ 65, 83, 68 ];
      controls.addEventListener("change", render);
    }

    function render() {
      renderer.render(scene, camera);
    }

    //窗口变动触发的函数
    function onWindowResize() {
      camera.aspect = window.innerWidth / window.innerHeight;
      camera.updateProjectionMatrix();
      controls.handleResize();
      render();
      renderer.setSize(window.innerWidth, window.innerHeight);
    }

    function animate() {
      //更新控制器
      controls.update();
      render();

      //更新性能插件
      stats.update();
      requestAnimationFrame(animate);
    }

    function draw() {
      initRender();
      initScene();
      initCamera();
      initLight();
      initModel();
      initControls();
      initStats();

      animate();
      window.onresize = onWindowResize;
    }
  </script>
</html>
